1. Field of Invention
This invention relates to a fail safe apparatus for use in initiation of a rocket motor ignitor or of high explosive warheads and more particularly to a device that will not initiate a firing signal even through accidentally triggered by electromagnetic radiation or other environmental effects.
2. Background of Invention
Detonating fuzes have wide utility in many diverse applications where explosives or propellants are used. This is especially true in the aerospace, missile and rocket fields where the use of detonating fuzes require safing techniques that prevent inadvertant firing of a weapon such as a rocket or missile or the arming of a warhead in situations tha could cause damage to the launching source or injury to loading and servicing personnel of the weapon. Many known safe arming devices and techniques used in the safing of warhead detonators are not suitable when applied to the safing of rocket motor igniters. Warhead devices can utilize forces derived from a post launch environment such as boost acceleration caused by rocket motor firing to drive mechanical explosive alignment devices for arming the warhead by establishing an explosive train continuity. These forces are usually not available before missile rocket motor firing.
Prior art attempts to solve the problem of reliable safing of rocket motor igniters has involved the use of mechanical devices such as pulling an alignment rod to align an explosive trail to the igniter whenever the missile is ejected or released from its launching apparatus on an aircraft. Other devices use the dynamic air pressure, caused by aircraft flight above a predetermined threshold velocity, to arm the rocket motor igniter prior to motor firing. These techniques are expensive and in many cases are not suitable for all missiles because of rocket launcher design or missile configuration which may make it unfeasible or impossible to achieve arming by means of movement of mechanical arming devices.